/**
*      author: Y_Yao
*      created: 2025-01-24 12:11:41
**/

#include<bits/stdc++.h>

#define int LL
using namespace std;
using LL = long long;
const LL LLINF = 1e18;
const int INF = 0x3f3f3f3f;
const int N = 100 + 7;
int a[N],b[N];
int n;

void solve()
{
    cin >> n;
    for(int i = 1;i <= n;i++)
    {
        cin >> a[i];
    }
    for(int i = 1;i <= n;i++)
    {
        cin >> b[i];
    }

    int ans = 0;
    for(int i = 1;i < n;i++)
    {
        if(i + 1 <= n && a[i] > b[i + 1])
        {
            ans += a[i] - b[i + 1];
        }
    }
    ans += a[n];
    cout << ans << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    cin >> t;
    while(t--)
    {
        solve();
    }
    return 0;
}